HD255-5

WA250

GROSS HORSEPOWER241 kW 323 HP

NET HORSEPOWER235 kW 316 HP

MAX. GROSS VEHICLE WEIGHT47525 kg 104,770 lb

Photo may include optional equipment.

OFF-HIGHWAY TRUCK

HD255

OPERATOR ENVIRONMENT

Powerful KOMATSU SAA6D125E-3 Engine

This engine delivers quicker acceleration and higher travelspeed with the highest output per weight. Advanced technol-ogy, such as Common-Rail fuel Injection system, air-to-airaftercooler, and an effi-cient turbochargerenables the engine tomeet the North AmericanEPA Tier 2 emission reg-ulations. High torque atlow speed, impressiveacceleration, and low fuelconsumption ensuresmaximum productivity.

6-Speed, Fully Automatic K-ATOMiCSTransmission with Shift-Limiter Function

The K-ATOMiCS (Komatsu Advanced Transmission with Op-timum Modulation Control System) automatically selects opti-mum gear according to vehicle speed, engine speed andshift position you’ve chosen. A shift-limiter function isequipped as a standard. It enables to maintain 1st gearwhen the vehicle desends a steep grade.

Oil-Cooled Multiple-Disc Retarder and ExhaustBrake

The large capacity continu-ously oil-cooled wet multipledisc retarder and the exhaustbrake are equipped as stan-dard and enable safe andcontinuous faster downhilldrive.

High Strength QuarryBody for Easy Loading Operation

The robust body is constructed of thick wear-resistant steelhaving 500 Brinell hardness. The V-shape, flat-bottom designalso increases structural strength, and provides excellentload stability.

Outstandingly Small Turning Radius

The A-frames employed tothe front wheels give alarge steering angle, andrealizes the outstandinglysmall turning radius. Itenables to position thetruck at a desired placeeasily and quickly.

Wide, Specious Cab with Excellent Visibility

The cab is integrated with ROPS and the structures conformto ISO 3471 and SAE J1040 standards. The driver’s com-partment makes it very easy andcomfortable for the operator touse all the controls. The widewindshield and large rearviewmirrors provide the superior visi-bility and safety operation.

Suspension Seat

The suspension, fabric-covered seat which is adjustable tothe operator’s weight is provided as standard. The suspen-sion seat dampens vibrations transmitted from the machineand reduces operator fatigue as well as holding the operatorsecurely to assure confident operation.

Automatic Supplementary Steering and SecondaryBrakes

Automatic supplementary steering and secondary brakes areemployed as a standard.If an abnormality occurs in the steering hydraulic circuits orengine stops suddenly, this supplementary steering systemworks automatically and enables to continue steering operation.

Steering: ISO 5010, SAE J1511, SAE J53 Brakes: ISO 3450, SAE J1473

Hydropneumatic Suspension for All Terrains

The hydropneumaticsuspension assurescomfortable ride evenover rough terrain andensures maximum pro-ductivity and operatorconfidence.

PRODUCTIVITY FEATURESOFF-HIGHWAY TRUCK HD255-5

32

O F F - H I G H W AY T R U C KHD255-5

A-frame

7.0m 23'0"

Photo may include optional equipment.

⁄ Large-sized rear view mirror¤Rubber mudguard‹Rubber mudguard

(at right platform)

⁄

¤

‹

ROPS

Komatsu Components

Komatsu manufactures engine, torque converter, transmis-sion, hydraulic units, and electrical devices on this dump truck.Komatsu dump trucks are manufactured with an integratedproduction system under a strict quality control system.

High Strength Body

The side plates of the body are reinforced with cross ribs toincrease the rigidity. The ribs of the bottom plate also increasethe rigidity greatly. Furthermore, the body is made of new steelwhich we developed in cooperation with a Japanese steelmanufacturer having the best steel manufacturing technolo-gies in the world. This ultra hardwear-resisting steel has hard-ness 25% higher than the con-ventional steel and about 2.5times higher than the commonlining steel.

Sealed DT Connectors

Main harnesses and con-troller connectors areequipped with sealed DTconnectors providing highreliability, water resistanceand dust resistance.

High-Rigidity Frames

Cast-steel components are used in the main frame for high-stress areas where loads and shocks are most concentrated.It provides a superior reliability and durability.

Flat Face-to-Face O-Ring Seals

Flat face-to-face O-ring sealsare used to securely sealhydraulic hose and fuel linehose connections and to pre-vent oil or fuel leakage.

EXCELLENT RELIABILITY AND DURABILITY

54

O F F - H I G H W AY T R U C KHD255-5

25mm 0.98"

14mm 0.55"16mm 0.63"

O-ring

Nipple

Hose

Cast steel

EASY MAINTENANCE

Extended Oil Change Intervals

In order to minimize operating costs, oil change intervalshave been extended.

Engine oil change intervals: 250 hours // 500 hours

Wet Multiple-Disc Brakes

The wet multiple-disc brakes on rear wheels make mainte-nance and adjustment unnecessary.

Flange Type Rim

The flange type rims provide easy removal/installation of thetires.

Centralized Arrangementof Filters and GreasingPoints

The engine oil filter and fuel fil-ter are centralized on the leftside of the machine so thatthey can be serviced easily.

The greasing points are alsocentralized at two locations.

These filter and greasing main-

tenances can be done from the

ground level.

OFF-HIGHWAY TRUCK HD255-5

VALUE-ENHANCING OPTIONS

ARSC (Auto Retard Speed Control)

ARSC, which enables to maintain the constant downhill trav-el speed, is available as an option. It allows the operator tosimply set downhill travel speed. Even after setting the trav-el speed, the operator can still adjust it finely at incrementsof 1 km/h 0.4MPH per click (±5 km/h 3.1 MPH within max.travel speed) to match the optimum speed for the slope.Also, since temperature of retarder cooling oil is always mon-itored, the speed is automatically lowered.

Settable range: 7 km/h 4.3 MPH to 45 km/h 28.0 MPH

Desiccant Type Air Dryer

Desiccant type air dryer is available asan option. It enables to get rid of themoisture and oil content in the com-pressed air that are provided from theair compressor. Therefore, reliabilityand durability of the air circuit isimproved spectacularly.

Front Brake Ratio Valve

The front brake ratio valve lowers the air pressure at the be-ginning of braking operations to limit the efficiency of thefront brake to reduce heating and wear of the brake pad. Ifthe brake pedal is pressed more than half, however, the airpresser isn’t lowered, but the front brake works as designed.

Automatic Greasing System

This releases operators and mechanics from burdensomegreasing work on the undercarriage. Maintenance time isshortened, and productivity is enhanced.

Go down sloop at constant speed

UP

SETDOWNCANCEL

Display of set travel speed

ARSC set lever

SPECIFICATIONSOFF-HIGHWAY TRUCK HD255-5

76

O F F - H I G H W AY T R U C KHD255-5

AXLES

Rear Axle type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Full-floatingFinal drive type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planetary gearRatios:

Differential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.900Planetary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.941

TRANSMISSION

Torque converter . . . . . . . . . . . . . . . . . 3-elements, 1-stage, 2-phaseTransmission. . . . . . . . . . . . . . . . . . . . Full-automatic, planetary typeSpeed range . . . . . . . . . . . . . . . . . . 6 speeds forward and 1 reverseLockup clutch . . . . . . . . . . . . . . . . . . . . . . . . . Wet, single-disc clutchForward . . . . . . . . . . . . . . . . . . . . Torque converter drive in 1st gear,

direct drive in 1st lockup and all higher gearsReverse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Torque converter driveShift control . . . . . . . . . . . . . . . Electronic shift control with automatic

clutch modulation in all gearsMaximum travel speed . . . . . . . . . . . . . . . . . . 47.0 km/h 29.2 mph

WEIGHT (APPROXIMATE)

Empty weight . . . . . . . . . . . . . . . . . . . . . . . . . . . 22450 kg 49,490 lbMax. gross vehicle weight:

Standard tire . . . . . . . . . . . . . . . . . . . . . . . . 47525 kg 104,770 lbOptional tire . . . . . . . . . . . . . . . . . . . . . . . . . 48035 kg 105,900 lbNot to exceed max. gross vehicle weight, including options, fueland payload.

Weight distribution:Empty: Front axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48%

Rear axles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52%Loaded: Front axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32%

Rear axles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68%

ENGINE

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Komatsu SAA6D125E-3Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water-cooled, 4-cycleAspiration. . . . . . . . . . . . . . Turbo-charged and air-to-air after-cooledNumber of cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 mm 4.92"Stroke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 mm 5.91"Piston displacement. . . . . . . . . . . . . . . . . . . . . . . . . 11.04 ltr 674 in3

Flywheel horsepowerISO 9249 / SAE J1349. . . . . . . . . . . . . . . . Gross 241 kW 323 HP

Net 235 kW 316 HPRated rpm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2100 rpm

Maximum torque . . . . . 1375 N•m 140 kg•m 1,013 lb•ft at 1,400 rpmFuel system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct injectionGovernor . . . . . . . . . . . . . . . . . . . . . . . . . . . Electronically controlledLubrication system

Method . . . . . . . . . . . . . . . . . . . . . . . Gear pump, force-lubricationFilter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Full-flow type

Air cleaner. . . . . . . . . . . . . . . . . . Dry type with double elements andprecleaner, plus dust indicator

SUSPENSION SYSTEM

Independent hydropneumatic suspension cylinder with fixed throttle todampen vibration.

MAIN FRAME

Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Box-sectioned structure

STEERING SYSTEM

Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . Fully hydraulic power steeringwith two double-acting cylinders

Supplementary steering . . . . . . . Automatic control with manual switch (meets ISO 5010, SAE J1511 and SAE J53)

Minimum turning radius . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0 m 23'0"

BRAKES

Brakes meet ISO J3450 and SAE J1473 standards.Service brakes:

Front. . . . . . . . . . . . . . . . . . . . Air-over-hydraulic, caliper disc typeRear . . . . . . . . . . . Air-over-hydraulic, oil-cooled multiple-disc type

Parking brake . . . . . . . . . . . . Spring applied, internal-expanding brakeRetarder . . . . . . . . . . . . . . . . . . . . . . . . . Air-over-hydraulic, oil-cooled,

multiple-disc rear brakes act as retarder.Secondary brake . . . . A relay valve automatically actuates the service

brakes when air pressure drops below the rated level. Manual operation is also possible.

BODY

Capacity:Struck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2 m3 17.2 yd3

Heaped (2:1, SAE) . . . . . . . . . . . . . . . . . . . . . . . 17.7 m3 23.2 yd3

Payload . . . . . . . . . . . . . . . . . . . . . . . 25 metric tons 27.6 U.S. tonsMaterial . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 kg/mm2 227,500 psi

high tensile strength steelStructure. . . . . . . . . . . . . . . . . . . . . . . V-shape body with flat-bottomMaterial thickness:

Bottom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 mm 0.98"Front. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 mm 0.63"Sides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 mm 0.55"

Target area (inside length x width) . . . . . . . 4570 mm x 2995 mm 15'0" x 9'10"

Dumping angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49°Height at full dump . . . . . . . . . . . . . . . . . . . . . . . . . . 7075 mm 23'3"Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exhaust heating

HYDRAULIC SYSTEM

Hoist cylinder. . . . . . . . . . . . . . . . . . . Single, 3-stage telescopic typeRelief pressure . . . . . . . . . . . . . . . . 20.6 MPa 210 kg/cm2 2,990 psiHoist time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 sec

CAB

Dimensions comply with ISO 3471 and SAE J1040-1988c ROPS(Roll-Over Protective Structure) standards.

TIRES

Standard tire. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.00-25-28PR(E3)

SERVICE REFILL CAPACITIES

Fuel tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 ltr. 98.8 U.S. GalEngine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 ltr. 7.1 U.S. GalTorque converter, transmission and

retarder cooling. . . . . . . . . . . . . . . . . . . . . . . 70 ltr. 18.5 U.S. GalDifferential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 ltr. 4.8 U.S. GalFinal drives (total) . . . . . . . . . . . . . . . . . . . . . . . . 14 ltr. 3.7 U.S. GalHydraulic system . . . . . . . . . . . . . . . . . . . . . . . . 80 ltr. 21.1 U.S. GalSuspension (total) . . . . . . . . . . . . . . . . . . . . . . . . 30 ltr. 7.9 U.S. Gal

Standard equipment may vary for each country, and this specification sheet may contain attachments and optional equipmentthat are not available in your area. Please consult your Komatsu distributor for detailed information.

STANDARD EQUIPMENT FOR BASE MACHINE

OPTIONAL EQUIPMENT

CAB:● Air conditioner● Cigarette lighter and ashtray● Intermittent windshield wiper● Passenger seat (Fabric)● Radio, AM / AM&FM● Seatbelt (Two point anchor /

78mm 3.1")

BODY:● Without body heating

(with muffler)● Body liner

GUARD AND COVERS:● Body spill guard (150 / 250 mm

5.9" / 9.8")● Engine side cover● Platform guard (Right hand side)● Radiator shutter (Canvas type)● Vandalism protection

LIGHTING SYSTEM:● Fog lamp● Hazard lamp● Side work lamps● Yellow beacon

TIRES:● 16.00 R25 Radial tire

SAFETY:● Dumping caution buzzer ● Fire extinguisher● Front brake ratio valve

MAINTENANCE:● Air dryer, desiccant type● Auto greasing system● Jack, 30ton 33 U.S. tons● Large capacity batteries (Wet type)● PM-clinic

GAUGE ( MEASUREMENT EQUIPMENT):● Revo-taco-graph● Tacho-graph

OTHER:● ARSC (Auto retard speed control)● Cold area arrangement (-30˚C

thru 40˚C)● Hot area arrangement (-20˚C

thru 50˚C)● Poor fuel arrangement ● Sandy & dusty area arrangement● Tire chains

ENGINE:● Alternator 50A/24V● Batteries 2 x 12V 150AH● Komatsu SAA6D125E-3 ● Starting motor, 7.5kW● Engine auto preheater

CAB:● Floor mat● Foot rest● Reclining suspension seat● Retractable operator seat belt,

50mm 2" wide● ROPS cab● Sun-visor

● Tiltable and telescopic steeringwheel

● Tinted glass● Windshield washer and wiper

GUARD AND COVERS:● Engine under guard● Exhaust thermal-guard● Fire protective covers● Mudguards● Transmission under-guard

SAFETY:● Automatic supplementary

steering● Back up alarm

● Exhaust retarder● Handrails for platform● Horn, electric● Ladders, left and right hand side● Rear view mirrors● Secondary brake● Under view mirror

LIGHTING SYSTEM:● Back-up light● Headlights ● Indicator, stop and tail lights

BODY:● Body, 17.7m3 23.2 yd3 (Heaped

2:1 SAE), with exhaust heating

● Cab, guard, left side

TIRES:● 16.00-25-28PR

OTHER:● Caliper disc brake (Front) ● Centralized greasing● Fully automatic transmission with

all speeds electronic modulation● Hydropneumatic suspension

(Front and Rear)● Lock ejector● Oil-cooled multiple disc brake

(Rear)

DIMENSIONS

2700 mm 8'10"3200 mm 10'6" 495 mm

1'7"280 mm

11"7390 mm 24'3"

3600 mm 11'10" 2140 mm 7'0"1650 mm5'5"

7075

mm

23'

3"

2940

mm

9'8"

525

mm

1'9"

2225

mm

7'4

"29

95 m

m 9

'10"

32

00 m

m 1

0'6"

3590

mm

11'

9"33

75 m

m 1

1'1"

4570 mm15'0"

6770 mm 22'3"

7000 mm23'0"

49

61

515

mm

1'8"

16.00-25-28PR

16.00-25-28PR

HESS611202 Materials and specifications are subject to change without notice.is a trademark of Komatsu Ltd. Japan.

www.Komatsu.com Printed in Japan 200410 IP.As(15)

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TRAVEL PERFORMANCE

Grade distance: 600 m (1970 ft) Grade distance: 900 m (2950 ft) Grade distance: 1500 m (4920 ft)

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Grade distance: Continuous Descent Grade distance: 450 m (1480 ft)

To determine travel performance: Read fromgross weight down to the percent of totalresistance. From this weight-resistance point,read horizontally to the curve with the highest obtainable speed range, then downto maximum speed. Usable rimpull dependsupon traction available and weight on drivewheels.

To determine brake performance: Thesecurves are provided to establish the maximum speed and gearshift positionfor safer descents on roads with a given distance. Read from gross weight downto the percent of total resistance. Fromthis weight resistance point, read horizontally to the curve with the highestobtainable speed range, then down tomaximum descent speed the brakes cansafely handle without exceeding coolingcapacity.

BRAKE PERFORMANCE

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789

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